Step |
Hyp |
Ref |
Expression |
1 |
|
ablsimpnosubgd.1 |
|- B = ( Base ` G ) |
2 |
|
ablsimpnosubgd.2 |
|- .0. = ( 0g ` G ) |
3 |
|
ablsimpnosubgd.3 |
|- ( ph -> G e. Abel ) |
4 |
|
ablsimpnosubgd.4 |
|- ( ph -> G e. SimpGrp ) |
5 |
|
ablsimpnosubgd.5 |
|- ( ph -> S e. ( SubGrp ` G ) ) |
6 |
|
ablsimpnosubgd.6 |
|- ( ph -> A e. S ) |
7 |
|
ablsimpnosubgd.7 |
|- ( ph -> -. A = .0. ) |
8 |
|
elsni |
|- ( A e. { .0. } -> A = .0. ) |
9 |
7 8
|
nsyl |
|- ( ph -> -. A e. { .0. } ) |
10 |
|
eleq2 |
|- ( S = { .0. } -> ( A e. S <-> A e. { .0. } ) ) |
11 |
6 10
|
syl5ibcom |
|- ( ph -> ( S = { .0. } -> A e. { .0. } ) ) |
12 |
9 11
|
mtod |
|- ( ph -> -. S = { .0. } ) |
13 |
12
|
pm2.21d |
|- ( ph -> ( S = { .0. } -> S = B ) ) |
14 |
|
idd |
|- ( ph -> ( S = B -> S = B ) ) |
15 |
|
ablnsg |
|- ( G e. Abel -> ( NrmSGrp ` G ) = ( SubGrp ` G ) ) |
16 |
15
|
eqcomd |
|- ( G e. Abel -> ( SubGrp ` G ) = ( NrmSGrp ` G ) ) |
17 |
3 16
|
syl |
|- ( ph -> ( SubGrp ` G ) = ( NrmSGrp ` G ) ) |
18 |
5 17
|
eleqtrd |
|- ( ph -> S e. ( NrmSGrp ` G ) ) |
19 |
1 2 4 18
|
simpgnsgeqd |
|- ( ph -> ( S = { .0. } \/ S = B ) ) |
20 |
13 14 19
|
mpjaod |
|- ( ph -> S = B ) |